The FIA intends to confirm the power unit performance analysis after the Miami Grand Prix, even if Miami no longer sits as the sixth race of the season because Bahrain and Saudi Arabia were removed from the calendar. That decision would lock in the first Aduo observation window based on the data gathered so far.

What is Aduo?

Aduo stands for Additional Development and Upgrade Opportunities. It is the mechanism that allows engine manufacturers to bring updates to the thermal part of their already-homologated power units during the season. The FIA uses a Performance Index to compare each supplier’s power unit performance against a benchmark and to determine who gets development tokens.

Why Miami matters

Because two races were cancelled, the original six-race observation window would have slid forward unless the FIA intervened. Motorsport Magazin reported that the FIA may vote to close the first Aduo window after Miami. Practically speaking, that means the Performance Index would be calculated with data from four races instead of six, and the resulting allocations of update opportunities would be confirmed there.

Who gets upgrades

The Performance Index drives who can develop and how much:

  • If a supplier’s power unit is between 2% and less than 4% slower than the best reference, they will receive one in-season update and one update for the following season.
  • If a supplier is more than 4% off the benchmark, they will get two in-season updates and two development tokens for 2027.

What the Performance Index includes

Although Aduo focuses on the thermal part of the engine, the Performance Index also accounts for electric-side factors such as ERS-K efficiency maps and related parameters. In short, overall power unit performance is measured, not only raw thermal power.

Timing and practical limits

Thermal engine changes generally take longer to design and validate than aerodynamic updates. The regulations allow a team to introduce an Aduo-authorized development from the first race after the observation window closes. With the first window expected to close after Miami, the next event where upgrades could appear would be Monaco.

What can be changed under Aduo

The technical appendix lists a range of thermal components permitted for development. Examples include:

  • V6 assembly: monobloc, cylinder head, crankshaft, camshafts
  • Combustion-related parts: combustion chamber surface, pre-chamber in the head, pistons, connecting rods
  • Ancillary systems: water pump, oil pump
  • Fuel system elements located downstream of the high-pressure pump
  • Aspiration system, camshaft profiles, flywheel

In addition to hardware changes, a manufacturer granted Aduo development will receive extended access to engine test benches for work that would normally face restrictions.

Where this is headed

The overall goal of the mechanism is to narrow performance gaps between power units to within a 2% window. There are two more observation periods planned: one after the 12th race and another after the 18th race. At the end of each observation period, the FIA will use the accumulated data to decide whether to award further development tokens.

So, yes, Miami could be the moment when the first round of engine upgrades is officially decided, even if the calendar no longer matches the original plan. Teams that are lagging will be watching closely for their chance to catch up.